Haldol (haloperidol) is a first-generation (typical) antipsychotic medication belonging to the butyrophenone class. It is primarily indicated for the management of manifestations of psychotic disorders, such as schizophrenia, and for the control of tics and vocal utterances in Tourette’s Syndrome. It is also utilized in the short-term treatment of severe agitation or hyperactivity in pediatric populations. Haldol functions primarily as a potent dopamine D2 receptor antagonist within the mesolimbic pathway of the brain, which is believed to underlie its efficacy in reducing positive symptoms of psychosis, including hallucinations, delusions, and disorganized thinking. Its long history of clinical use has established it as a cornerstone agent in psychiatric and emergency medicine for rapid tranquilization and long-term maintenance therapy.

Features

• Active pharmaceutical ingredient: Haloperidol
• Available formulations: Immediate-release oral tablets, concentrate oral solution, short-acting intramuscular (IM) injection, and long-acting decanoate (IM) injection
• Standard tablet strengths: 0.5 mg, 1 mg, 2 mg, 5 mg, 10 mg, 20 mg
• Haloperidol decanoate injection: 50 mg/mL and 100 mg/mL strengths for extended-release
• High potency typical antipsychotic with strong dopamine D2 receptor blockade
• Also exhibits activity at alpha-1 adrenergic receptors

Benefits

• Provides rapid and effective reduction of positive psychotic symptoms, including hallucinations and delusions.
• Offers a reliable option for the acute management of severe agitation and violent behavior in emergency settings.
• The availability of a long-acting injectable (LAI) formulation (decanoate) enhances treatment adherence for maintenance therapy.
• Can be effective in managing Tourette’s Syndrome, reducing the frequency and severity of tics.
• Its established efficacy and wide availability make it a cost-effective treatment option within formularies.
• Provides a clear therapeutic option for patients who may not tolerate or respond to newer atypical antipsychotics.

Common use

Haldol is commonly prescribed for the treatment of schizophrenia and related psychotic disorders. It is also FDA-approved for the management of tics associated with Tourette’s Disorder in children and adults. Beyond its labeled indications, it is frequently used off-label for the acute treatment of severe agitation and delirium in hospital settings, including intensive care units and emergency departments. It may also be considered for the management of behavioral disturbances in patients with dementia (though with extreme caution due to black box warnings), Huntington’s disease, and certain organic psychoses.

Dosage and direction

Dosage must be highly individualized based on diagnosis, severity of symptoms, patient age, and clinical response. Therapy should be initiated at the lowest effective dose.

• Oral (Adults - Psychosis): Initial dose often ranges from 0.5 mg to 5 mg, administered two or three times daily. Dosage may be adjusted upward, often in increments of 1-2 mg every few days as tolerated. The usual maintenance dose range is 5 mg to 20 mg daily, though some patients with severe, resistant illness may require higher doses under close supervision. The total daily dose is typically divided into 2 or 3 administrations.
• IM Injection (Adults - Acute Agitation): 2 mg to 5 mg doses are common, which may be repeated every 60 minutes or as needed. Doses above 10 mg per injection are rarely necessary.
• Haloperidol Decanoate (LAI): Used only for patients stabilized on oral haloperidol. The initial LAI dose is typically 10 to 15 times the previous stable daily oral dose, administered intramuscularly every 4 weeks. The dose and dosing interval are then adjusted based on response.
• Elderly/Debilitated Patients: Initiate with much lower doses (e.g., 0.5 mg to 1 mg once or twice daily) with very slow and cautious titration.
• Pediatric Patients (for non-psychotic disorders): Dosing is based on weight and is typically much lower than adult doses. A physician will determine the precise regimen.

The oral concentrate must be diluted with water, juice, or a soft drink before administration. Tablets should be swallowed whole. Always follow the specific dosage instructions provided by the prescribing physician.

Precautions

• Elderly Patients with Dementia-Related Psychosis: Haldol carries a Black Box Warning stating that elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Haldol is not approved for this use.
• Extrapyramidal Symptoms (EPS): High risk of causing drug-induced movement disorders, including Parkinsonism, akathisia (motor restlessness), acute dystonic reactions, and tardive dyskinesia. Risk is dose-related.
• Neuroleptic Malignant Syndrome (NMS): A rare but life-threatening neurological disorder characterized by hyperpyrexia, muscle rigidity, altered mental status, and autonomic instability. Requires immediate discontinuation of the drug and intensive medical treatment.
• QT Prolongation: Haldol can prolong the cardiac QT interval, which may increase the risk of developing torsades de pointes, a potentially fatal arrhythmia. Caution is advised in patients with cardiac conditions or those on other QT-prolonging drugs. Baseline and periodic ECGs may be recommended.
• Tardive Dyskinesia (TD): A potentially irreversible, involuntary movement disorder that may develop with chronic treatment. The risk appears to be highest among the elderly, especially women.
• Cognition and Sedation: May cause drowsiness, sedation, and impair mental and/or physical abilities. Patients should be cautioned about operating machinery or driving until they know how the drug affects them.
• Orthostatic Hypotension: May cause a drop in blood pressure upon standing, leading to dizziness and falls, especially during initial dose titration.

Contraindications

Haldol is contraindicated in patients with:

• Known hypersensitivity to haloperidol or any components of the formulation.
• Severe central nervous system depression or comatose states.
• Parkinson’s disease (can severely worsen symptoms).
• Known or suspected QT prolongation (including congenital long QT syndrome), significant cardiac arrhythmias, or recent acute myocardial infarction.

Possible side effect

Common side effects may include:

• Extrapyramidal symptoms (EPS): restlessness (akathisia), muscle stiffness, tremor, slowed movement, acute dystonia (muscle spasms)
• Sedation, drowsiness, dizziness
• Dry mouth, blurred vision, constipation
• Insomnia, headache, anxiety
• Weight gain
• Hyperprolactinemia (elevated prolactin levels leading to galactorrhea, gynecomastia, menstrual irregularities)

Serious side effects requiring immediate medical attention:

• Signs of Neuroleptic Malignant Syndrome (NMS): high fever, stiff muscles, confusion, sweating, irregular heartbeat
• Signs of tardive dyskinesia: involuntary movements of the tongue, face, mouth, jaw, or extremities
• Irregular or fast heartbeat, palpitations, fainting
• Severe dizziness upon standing
• Seizures
• Significant weight gain
• Jaundice (yellowing of skin or eyes)

Drug interaction

Haldol has numerous potential drug interactions. Key interactions include:

• Other CNS Depressants: (e.g., alcohol, benzodiazepines, opioids, sedating antihistamines) can potentiate sedation and respiratory depression.
• QT-Prolonging Agents: (e.g., certain antiarrhythmics [amiodarone, sotalol], antibiotics [macrolides, fluoroquinolones], antidepressants [citalopram], other antipsychotics) can have additive effects on QT interval, increasing arrhythmia risk.
• Dopamine Agonists: (e.g., levodopa, bromocriptine) Haldol may antagonize their effects, reducing efficacy in treating Parkinson’s disease.
• Enzyme Inhibitors: Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, clarithromycin) can significantly increase haloperidol plasma levels, increasing the risk of toxicity and side effects.
• Enzyme Inducers: Strong CYP3A4 inducers (e.g., carbamazepine, rifampin, St. John’s Wort) can decrease haloperidol plasma levels, potentially reducing its efficacy.
• Anticholinergic Drugs: (e.g., benztropine, used to treat EPS) may be co-administered but can also increase the risk of other side effects like constipation and confusion.

Patients must provide their doctor with a complete list of all medications, including prescription, over-the-counter, and herbal products.

Missed dose

If a dose is missed, it should be taken as soon as it is remembered. However, if it is almost time for the next scheduled dose, the missed dose should be skipped, and the regular dosing schedule resumed. Do not double the next dose to make up for a missed one. For patients on once-daily dosing, this is particularly important. If multiple doses are missed, contact a physician for advice on how to safely restart therapy.

Overdose

Overdose of Haldol is severe and potentially fatal. Symptoms are primarily extensions of its pharmacological effects and include:

• Severe central nervous system depression ranging from sedation to coma.
• Severe extrapyramidal symptoms (rigidity, agitation).
• Hypotension (low blood pressure) or hypertension (high blood pressure).
• Cardiac effects, including QT prolongation, arrhythmias, and torsades de pointes.
• Respiratory depression and arrest.

In case of suspected overdose, seek emergency medical attention immediately. Treatment is symptomatic and supportive. There is no specific antidote. Cardiovascular monitoring, including ECG for QT prolongation, is essential. Management of severe EPS may require anticholinergic agents.

Storage

• Store at room temperature (20°C to 25°C or 68°F to 77°F) away from light, moisture, and heat.
• Do not store in the bathroom.
• Keep the oral concentrate in its original container; do not transfer to other bottles.
• Keep all medications out of the reach of children and pets.
• Do not freeze the liquid formulation.
• Properly discard any unused medication after the expiration date or when no longer needed.

Disclaimer

This information is for educational and informational purposes only and does not constitute medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or medication. Never disregard professional medical advice or delay in seeking it because of something you have read here. The author and publisher are not responsible for any specific health or allergy needs that may require medical supervision or for any adverse effects resulting from the use of information contained herein.

Reviews

• Clinical Efficacy (4.5/5): Haldol is widely regarded by psychiatrists as a highly effective and potent antipsychotic, particularly for managing positive symptoms and acute agitation. Its rapid onset of action (especially IM) is a key strength in emergency settings.
• Side Effect Profile (2/5): The primary drawback is its high propensity for causing extrapyramidal side effects (EPS) and the risk of tardive dyskinesia. This has led to a preference for atypical antipsychotics as first-line agents for many patients when feasible.
• Formulation Flexibility (4/5): The availability of multiple formulations, including a reliable long-acting injectable, is a significant advantage for ensuring adherence in maintenance therapy for chronic conditions like schizophrenia.
• Overall Utility (4/5): Despite its side effect burden, Haldol remains an indispensable tool in psychiatry. It is often described as a “workhorse” medication—predictable, potent, and invaluable for treatment-resistant cases or when rapid control is paramount.